1. Field of the Invention
The present invention relates to electronic memory devices, and more specifically to electronic storage of parameters relating to operational environments.
2. Description of the Related Art
One of the fastest growing areas of computer technology relates to the explosive growth of modems. Modems provide direct digital communication over existing telephone lines among computers, and can allow access to the Internet, E-mails, and computer billboards, to name a few examples. Although the bandwidth of modems was originally thought to be limited to a few kilobits per second, recent advances have allowed modems to achieve speeds approaching 56 kilobits per second, although 14.4 and 28.8 kilobits per second are more common. Still other higher speeds may yet be possible, given the explosive growth in this area.
Unfortunately, standards still are evolving for some of the higher speed technologies. For example, several manufacturers have been developing modems having higher speed protocols, independent of any particular standard. Higher speed digital communications is seen as a necessity, particularly in light of the dramatic development of the Internet, yet the pace of innovation has exceeded the ability to set standards. In Europe, development of the GSM Standard is underway while in the United States, the rapid pace of technological advancement far exceeds the ability of the standard-setting entities to provide appropriate standards. Further, standards obviously cannot be developed for presently unknown technologies. Interoperability is a problem as manufacturers of modems try to create systems to allow one computer to communicate with a computer operating under a different format. For an overview of modem technology, refer to U.S. Pat. No. 5,428,671 entitled "Modem for Tight Coupling Between a Computer and a Cellular Telephone," issued Jun. 27, 1995, to Don A. Dykes, et al., which is hereby incorporated by reference.
Not only have the lack of standards encouraged independent development of incompatible communications protocols among various manufacturers within a given country, but global harmonization of communication protocols is difficult to achieve, and as consumers and businesses in one country try to take advantage of technological advances in another country having a different communication system, manufacturers of consumer and business related devices must anticipate demands for their products in a variety of potential uses.
Similar problems are also evident in other areas of technology. For example, the lack of international standards relating to cellular telephones makes it difficult for a manufacturer in one country to develop cellular products, including modems, for use by international travellers who carry such devices cross international boundaries and into different operational environments. The use of different operational environments in different countries inhibits both the ability of a manufacturer to produce a product for sale in several countries, and the development of products that can be used transported by an end-user across international boundaries. Lack of international standards relating to handshake/initialization, handoff, security, and even bandwidth use make international interoperability particularly problematic.
Various approaches to solving these problems have been advanced. For example, some devices have a number of different protocols stored in memory or storage devices, such as flash devices, and EEPROMs, floppy discs, and others. These memory and storage devices can be loaded with a protocol for a particular customer's use at the point of manufacture. Drawbacks associated with these devices, however, are known: simple ROM is not updatable; RAM is volatile, and can be expensive, DRAM must be refreshed, and SRAM requires several transistors and can be expensive; EEPROMS require high internal voltages to increase speed, or have redundant devices with consequent complexity; magnetic memory has slow access time and requires greater power. Flash memories allow for nonvolatile storage, but erasing an entire block of flash memory can result in overwriting, or overcycling limiting the useful life of the flash memory. Complete reprogramming of a device upon each change of the environment in which the device will operate can be an inefficient process.